from tkinter import*
import tkinter.messagebox as messagebox
#from tkinter import messagebox


class Application(Frame):
    def __init__(self,master=None):
        Frame.__init__(self, master)
        self.pack()
        self.createWidgets()

    def createWidgets(self):
#        self.helloLabel = Label(self,text='Hello, world')
#        self.helloLabel.pack()
#        self.quitButton = Button(self,text='Quit',command=self.quit)
#        self.quitButton.pack()
        self.nameInput = Entry(self)
        self.nameInput.pack()
        self.alertButton = Button(self,text='Hello',command = self.hello)
        self.alertButton.pack()

    def hello(self):
        name = self.nameInput.get() or 'world'
        messagebox.showinfo('Message','Hello,%s' % name)

app = Application()
#设置窗口标题
app.master.title('Hello World')
#主消息循环：
app.mainloop()